1. Field of the Invention
The present invention relates to a droplet printing apparatus using capillary electric charge concentration, and more particularly, to a droplet printing apparatus using capillary electric charge concentration to stably supply a solution to be ejected to a nozzle using a capillary force.
2. Description of the Related Art
A droplet printing apparatus is used to eject very small droplet units of a solution on a substrate, wherein the substrate may be a variety of materials including microscope slides, biochips, paper, or other various materials. There are various droplet ejection methods. In an ink jet method, heat is supplied to a solution (ink) which is then ejected on a piece of paper or other material. However, this method is not appropriate when the characteristic of a solution to be ejected changes with heat. In particular, when a solution droplet includes a biomolecule such as a nucleic acid, a protein, a living cell, a virus, or bacteria a droplet printing apparatus wherein a solution can be ejected without heating is required.
An example of such an apparatus ejects picoliter-sized droplets using ultrasonic energy. In addition, a printing apparatus which ejects picoliter-sized droplets using electric charge concentration has been proposed in Korean Patent Application No. 2005-74496.